RIO: Scandal overshadowed the Rio Olympics Thursday as two US swimmers faced further questioning by Brazilian police after a judge raised doubts about their claims of being mugged, while a new report said a British athlete had been held up at gunpoint.

A top International Olympic Committee official was also arrested on Wednesday in a black market ticket sales probe, posing major distractions from the sport in Rio with Usain Bolt casting his sights on a new gold medal.

According to the Guardian newspaper, a British athlete was accosted by an armed assailant while out on the town early Tuesday.

Details were not immediately available but a British Olympic team spokesman told the BBC there had been an “incident of theft” and that the athlete concerned was “safe and well”. On Wednesday, American swimmers Jack Conger and Gunnar Bentz were taken off a flight leaving Rio de Janeiro.

Conger and Bentz, along with star US swimmer Ryan Lochte and squad member James Feigen, said they were held up at gunpoint in the early hours of Sunday.

However Brazilian judge Keyla Blank ordered the passports of all four to be seized to prevent them leaving the country.

The Globo media organisation posted a video online showing Conger and Bentz walking into a police station on Wednesday.

They were released late at night “with the understanding that they would continue their discussions about the incident on Thursday”, said Patrick Sandusky, spokesman for the US Olympic Committee.

Lochte, who had returned to the US before Brazilian authorities ordered the swimmers' questioning, and Feigen, who remains in Brazil, will cooperate with the investigation, US broadcaster NBC reported.

The four made headlines with their terrifying account while returning from a party.

Lochte said they were held up by muggers posing as police as they left a party just after 4:00 am. In interviews, he described how he had a gun put to his head and handed over his money and wallet.

‘Victims laughed’

However, the judge said their story was full of inconsistencies. And Britain's Daily Mail obtained video surveillance showing the four laughing as they returned to their accommodation at 6:56 am on Sunday.

Speaking to NBC late Wednesday, Lochte denied the swimmers fabricated their story.

“I wouldn't make up a story like this nor would the others – as a matter of fact we all feel it makes us look bad,” he was quoted as saying.

Also Wednesday, top European Olympic official Patrick Hickey was arrested over a black market ticket sale scandal.

The IOC executive member, head of the European Olympic Committees and the Irish national committee, spent Wednesday night in hospital after being detained at his luxury hotel.

Accused of ticket scalping, ambush marketing and conspiracy after tickets were seized from another Irish businessman, Hickey has “temporarily” stood down from his posts.

Following a raid similar to the arrest of seven top FIFA officials at a Zurich hotel last year, Hickey was shown in media video answering his hotel room door unclothed before putting on a bath robe.

Police said they suspect he had changed rooms to try to evade arrest. Hickey's wife was in another room and at first told them Hickey had left the country, police told reporters.

Brazilian police have launched a widening investigation after seizing more than 1,000 premier tickets for Games events, including the opening ceremony.

Tickets with a face value of about $1,000 dollars were sold for $8,000, in a racket prosecutors said yielded profits of $3.0 million.

The head of a sports ticketing firm, THG Sports, was detained with the tickets on August 5.

Hickey's son once worked for THG, but the sports powerbroker denied any wrongdoing in an interview with Irish television last week as the scandal mounted.

The arrests diverted attention from the sporting action as Bolt reached the final of the 200m – the second of his targeted three-gold-medal sweep of the Olympic sprint titles.

While Bolt ran the season's best 19.78 sec, his American arch-rival Justin Gatlin, 34, failed to reach the final.

Gatlin, who won the 100m silver behind Bolt at the weekend, said he had not fully recovered from an ankle injury suffered in November.

“I definitely think I can try for the world record, I definitely feel that,” Bolt said.

Drug-tainted Russia's only competitor in the track and field, Darya Klishina, failed to reach the final medal battle in the long jump. The 25-year-old blamed the turmoil of the doping scandal for her disappointment.

The IAAF gave her the green light for Rio and then banned her because of “new” doping information. She went to the sports tribunal to reverse the ban.

Brazil's suffering sports fans got some good news when football star Neymar scored twice – including the fastest Olympic goal after 15 seconds – in a 6-0 win over Honduras in the Olympic semi-final.

They take on Germany in the final in a revenge repeat of their disastrous 7-1 loss in the World Cup semi-final two years ago.